ibatis 一对多查询

<typeAlias alias="businessScopeItem" type="com.sdfrdj.vo.BusinessScopeItem"/>
    <typeAlias alias="businessScopeSubItem" type="com.sdfrdj.vo.BusinessScopeSubItem"/>
    

    <resultMap class="businessScopeItem" id="allItemResultMap">
       <result property="item_id"        column="ITEM_ID"/>
       <result property="item"           column="ITEM"/>
       <result property="unit_id"     column="UNIT_ID"/>
       <result property="seq"         column="SEQ"/>
       <result property="createdate"       column="CREATEDATE"/>
       <result property="isdel"   column="ISDEL"/>
       <result property="businessScopeSubItemList" column="item_id"  select="getBusinessScopeSubItemByItemId"/>
    </resultMap>
    
    <resultMap class="businessScopeSubItem" id="subItemResultMap">
       <result property="subitem_id"   column="SUBITEM_ID"/>
       <result property="item_id"        column="ITEM_ID"/>
       <result property="subitem"     column="SUBITEM"/>
       <result property="content"         column="CONTENT"/>
       <result property="rules"            column="RULES"/>
       <result property="limitdate"    column="LIMITDATE"/>
       <result property="createdate"       column="CREATEDATE"/>
       <result property="isdel"   column="ISDEL"/>
    </resultMap>

<!-- 查询所有业务范围事项子事项-->
    <select id="selectAllBusinessScopeList"  resultMap="allItemResultMap" parameterClass="businessScopeItem">
        SELECT 
                ITEM_ID,
                ITEM,
                UNIT_ID,
                SEQ,
                TO_CHAR(CREATEDATE,'yyyy-MM-dd') CREATEDATE,
                ISDEL
        FROM T_BUSINESS_SCOPE_ITEM
        WHERE 1=1
         <isNotEmpty prepend="and" property="unit_id">
                UNIT_ID=#unit_id#
        </isNotEmpty>
        <isNotEmpty prepend="and" property="item">
                 ITEM like '%$item$%'
        </isNotEmpty>
         <isNotEmpty prepend="and" property="isdel">
                ISDEL=#isdel#
        </isNotEmpty>
        ORDER BY ITEM_ID
    </select>
    
    <!-- 根据事项查询所有子事项-->
    <select id="getBusinessScopeSubItemByItemId"  parameterClass="java.lang.String" resultMap="subItemResultMap">
        SELECT 
                SUBITEM_ID,
                ITEM_ID,
                SUBITEM,
                CONTENT,
                RULES,
                LIMITDATE,
                TO_CHAR(CREATEDATE,'yyyy-MM-dd') CREATEDATE,
                ISDEL
        FROM T_BUSINESS_SCOPE_SUBITEM
        WHERE ITEM_ID=#item_id# AND ISDEL='0'
        ORDER BY SUBITEM_ID
    </select>